Chrome has disparate "this tab needs your attention" indicators.

- If a pinned background tab has a name change, Views shows a blue dot until the tab is activated, while the Mac pulses the tab once.
- If a background tab has a tab-modal dialog, with Views it pulses continuously, while with the Mac there is no appearance change.

I need an indication for background alert dialogs ( bug 747117 ) so that will be a third requirement.

My plan is to clean up and unify the platform behaviors. The plan:

- For pinned background tab name changes, do what Views does, and dot the tab until the tab is activated.
- For background tabs with dialogs, have them display a dot.

Note that this means that when a tab has a dialog, while it is in the background it shows a dot, which disappears when the tab is moved to the front, but it regains the dot when backgrounded. This seems less obtrusive than dotting the tab the whole time.